The Molecular Biology Core has been in operation for the past nine years and has provided state-of-the-art methodologies for numerous molecular biological techniques as well as recombinant protein expression and purification. The major goals of the Molecular Biology Core are: 1. To collect and maintain suitable plasmid vectors and host for expression of HIV/SIV and related recombinant proteins. 2. To provide a service for construction of recombinant plasmids and high level expression of HIV/SIV and related proteins. 3. To provide a service for purification of HIV/SIV and related proteins. 4. To establish an on-site repository for plasmids with HIV/SIV genes as well as recombinant HIV/SIV proteins. 5. To provide a service for construction of infectious HIV/SIV proviral clones containing defined mutations in genes of interest. 6. To train personnel to assist in the various phases of plasmid construction and expression/purification of recombinant proteins for the purpose of facilitating technology transfer. The Molecular Biology Core has assisted, on average, over 30 CFAR members per year during the last funding period. The Core has averaged over $30,000 per year in chargebacks over the last 3-1/2 years with a total of $122,677 to date for the current funding period. The Molecular Biology Core has provided critical reagents and expertise to UAB CFAR members which have funded individual R01 grants as well as participate in the UAB National Cooperative Vaccine Development, and National Cooperative Drug Discovery Group. Support of this facility is thus instrumental for the continued success of numerous investigators working in different areas of HIV pathogenesis, vaccine and drug studies currently conducted at UAB.